Yeah, I realize that depending on your toolchain it's not easily accessible. Ideally there would be a first-class implementation for each platform, but it looks like app stores are where we are headed. Though, that still leaves *nix package distribution, container images, language/framework and packaging as areas that can be helped by TUF.
We (Flynn) actually have a Go[0] implementation that you could use to either make a separate updater binary or even compile it into your app using the new alternative build modes coming in Go 1.5[1]. Our implementation also includes some tools to manage the metadata and signing so that you don't have to manually build it.